Impact
Vehicles, bikes or storage hit the track.

Noise and hardware
A bent track can make rollers bind, the door scrape and eventually come off track. Small bends sometimes start as noise; bigger ones stop the door. A technician can straighten or replace the section.
Short answer
Look at the track from a safe distance and note where the bend is. Stop using the door if rollers are catching or popping out. Avoid hammering the track yourself while the door is in it. Book track repair to realign or replace it.
Vehicles, bikes or storage hit the track.
Brackets allow the track to shift.
Rollers push against the track.
Walls or jambs shift over time.
Bends near the floor are often caused by vehicles, bikes or bins. Bends higher up, near the curve, are more often linked to loose brackets or a door that was forced while binding. The location of the bend helps the technician decide whether to straighten, replace a section or check the framing behind it. Clearing storage away from the tracks afterward helps prevent the same bend from happening again.
Describe what the door is doing when you call. A provider may ask follow-up questions, but a reliable price normally needs an on-site look rather than a phone-only quote.

Vertical tracks run up each side of the opening and curve into horizontal tracks under the ceiling.

Doors usually come off track after a vehicle bump, a broken cable, a worn roller or a misaligned track.

Most residential doors have between eight and fourteen rollers, depending on height and design.
Minor issues like a loose bracket may be simple, but straightening a track with the door in it is risky. A technician can do it safely.
Rollers may bind or pop out at the bend, and the door can come off track. The opener also has to push harder, which wears its gears and motor.
Small bends often can be corrected by a technician. Kinked, cracked or badly twisted sections are usually replaced, because a weakened track can let rollers slip out.
Impacts from vehicles, bikes or bins, loose brackets and worn rollers pushing against the track are the most common causes, along with framing that has shifted over time.
Yes. You often hear scraping, grinding or a clunk as rollers pass the bend, and the door may hesitate or shake at that point.
If the door still runs smoothly, book soon. If rollers are catching or the door binds, stop using it.

Call to schedule a technician visit with an independent provider who serves your area.